Batteries employ cathode-active materials to release and store cations during charge and discharge operations, respectively. Such cathode-active materials include transition metal oxides, which are commonly used in lithium-ion batteries to exchange lithium cations with an electrolyte. Transition metal oxides can include Mn, Ni, or Co, which have received particular attention due to their improved performance as cathode-active materials. This improved performance can result in higher energy densities, increased operating voltages, longer cycling lifetimes, and faster charge/discharge rates for the batteries involved. Other benefits are possible.
The performance of transition metal oxides can be influenced by a manner in which they are formed. Conventional methods of forming transition metal oxides involve solutions of transition metal salts, which are raised in pH to precipitate a transition metal precursor. Base additives, such as ammonium hydroxide, are used to effectuate this raise. However, these base additives typically offer little control over nucleation and growth processes in solution. Thus, particles precipitated using conventional methods may exhibit undesirable characteristics, including low densities, poorly-defined morphologies, broad particle size distributions, and deficient chemical stoichiometries. Such characteristics can limit an effectiveness of the transition metal precursor in producing a transition metal oxide that has improved performance (i.e., as a cathode-active material).